Bio-based polymers are polymeric materials whose carbon content is derived wholly or partly from renewable biological resources, including biomass-derived carbohydrates, lignocellulosic components, vegetable oils, proteins, or biologically produced monomers ^[1][2]. The term describes the origin of the polymer's feedstock rather than a particular molecular architecture, synthesis route, or end-of-life behavior. Accordingly, bio-based polymers may be naturally occurring polymers, chemically modified biopolymers, or synthetic polymers produced from bio-derived monomers ^[1][3]. Their polymer chains can be chemically identical or analogous to those of polymers conventionally produced from fossil resources, or they can possess structures not commonly obtained from petrochemical feedstocks ^[1]. Bio-based content may therefore be partial or complete and should be distinguished from the material’s total renewable-resource fraction. The designation does not, by itself, imply biodegradability, compostability, biocompatibility, or environmental superiority; these are independent properties requiring separate assessment ^[2][3]. Thus, bio-based polymers are defined primarily by the renewable biological origin of their constituent carbon, not by degradability or by a requirement that the polymer be naturally produced.